Humans care about trip latency, but there are different components. One person walking five minutes to a designated corridor may save ten people on a minibus three minutes on their trip each by avoiding unnecessary diversion. And this can add up quite a bit depending on how many passengers you are avoiding diverting for. There's a reason why (good) bus lines tend to be direct and on main roads.

The main reason why non-dense places don't see good bus service is because of labor costs. In developed countries labor is easily the biggest source of cost when it comes to a bus, so agencies will run one 40-passenger bus every half hour rather than three 15-passenger buses every ten minutes. Removing labor makes the latter scenario affordable, and if buses are coming every ten minutes average wait time is about five minutes, which is comparable to Lyft or Uber today in some places.